Increase in selenium requirements with physical activity loads in well‐trained athletes is not linear

Abstract

Selenium requirements in athletes are supposed to be increased with energy expenditure (EE) to preserve selenium status and an optimal antioxidant balance. The question of whether selenium intakes are related to EE and whether plasma selenium status induces up-regulation in erythrocyte endogenous antioxidant defense and decreases plasma oxidative damage markers in athletes was addressed. 118 well-trained athletes completed 7 d food and activities records in a cross-sectional study. Blood was sampled on day 8. Among the athletes, 23% of the males and 66% of the females had selenium intakes below two-third of the French RDA. Plasma selenium concentrations in most of less trained athletes were lower than the postulated concentration to be required to maximize erythrocyte GSH-Px activity. Athletes with the highest daily EE had the highest selenium intakes, percentage of vegetal protein intakes and plasma selenium concentrations. Only 2.6% of the athletes exhibited low plasma selenium concentrations (< 0.75 micromol/l). The relation between plasma selenium and EE was polynomial (r = 0.50; P < 0.005). Erythrocyte GSH-Px activity in athletes was not linked to selenium status. Selenium requirements are increased in athletes without being linearly related to EE.

Physical activity alters antioxidant status in exercising elderly subjects

“…None of elderly subjects exhibited marginal plasma Se concentrations ( b0.76 Amol/L), but plasma Se concentrations in most subjects were lower than the postulated concentration (1.15 Amol/L) to be required to maximize erythrocyte GSH-Px activity [34]. As previously shown [35], the dose-response association between plasma Se concentration and erythrocyte GSH-Px activity was not evidenced in athletes. However, this association was shown in SE subjects.…”

Does physical exercise modify antioxidant requirements?

“…However, others reported no effect of a daily supplementation (180 mg selenomethionine) during a 10-week training period with subjects originally less active on oxidative stress markers and on erythrocyte and muscle GSH-Px activities (89) . The increase in Se requirements with physical exercise is probably not linear (68) . The effect of the form of Se ingested (selenomethionine, selenocysteine, selenite, selenate) should be investigated as well as the effect of Se on other selenoproteins' functions.…”

“…An average Cu intake of 1·96 mg/d is found in highly trained subjects (energy expenditure . 16 740 kJ (4000 kcal)/d) (68) . Plasma Cu concentrations increase in response to exercise and return to initial values within a few days (75) .…”

Dietary intakes and antioxidant status in mind-body exercising pre- and postmenopausal women

“…In addition to these endogenous antioxidant effects, our previous studies showed that exercising improves the quality of dietary intake. Athletes who have high daily energy expenditures have been shown to consume food with high nutrient density regarding vegetal proteins, carbohydrates, vitamin C, folate and selenium, and reach recommended food nutrient intake levels more frequently than non exercising subjects (3)(4)(5). Consequently, the antioxidant response to regular exercise is suggested to be investigated in relation to dietary micronutrient intake (6).…”